1. Field of the Invention
The invention relates to an applicator and a device, respectively for cell treatment, in particular for epithelial cell removal or inactivation.
2. Background and Relevant Art
US 2002/0058890 A1 has disclosed a device for lithotripsy, which comprises an optical fiber and an absorber in the interior of a tubular housing. The optical fiber is connected to a laser at a first end and, at its other, second end, optically coupled to an inner side of the absorber facing the interior of the housing. When laser radiation from the laser impinges on the absorber on the inner side thereof facing the interior of the housing, the absorber generates a pressure wave, which is then, at the outer side of said absorber, transmitted through an end cap, encompassing the second end and the absorber, and emitted. Different shapes and/or propagation directions of the pressure wave can be achieved by different geometries of the end cap, for example in the style of lenses or cavities. The tubular housing does not have an emergence opening for the pressure wave; the absorber closes off the tubular housing at the free end thereof. As a result, a plasma possibly generated on the inner side of the absorber by the laser radiation remains in the interior of the housing.
WO 2004/071319 A1 has disclosed a surgical hollow needle for eye cataract treatment, with an optical fiber guided therein, wherein the optical fiber is coupled to a laser at its first end, situated outside of the hollow needle, and, at the second end thereof, the optical fiber is situated in the region of, and at a distance from, the tip of the hollow needle. In the region of the tip of the hollow needle, the latter has a target which is formed from a region of the wall of the hollow needle at the tip and at which a plasma is generated when irradiated by laser radiation of the laser from the fiber, as a result of which a pressure wave is created in turn. An opening, through which the pressure wave can reach the outside, is provided at the tip of the hollow needle. The lateral or side wall of the hollow needle is formed monolithically with the tip made of titanium (Ti) and embodied as continuous, smooth wall without an opening.
U.S. Pat. No. 5,324,282 has disclosed a surgical instrument in the form of a hollow needle for removing the lens of the eye by photolysis, which instrument has a tubular external wall with a longitudinal axis and a free end and also a laser fiber and a suction channel, which respectively extend longitudinally and in the interior of the needle up to the free end thereof. At the free end of the needle, a target made of titanium (Ti) is arranged at a distance from the free end of the laser fiber, wherein the laser light from the laser fiber impinges on the target. Furthermore, a tissue receiving opening, into which the suction channel opens, is provided at the free end of the needle, arranged obliquely and above the target and directly next to the latter. A suction pump is used to suction the tissue to be destroyed to the tissue receiving opening. When the tissue has now been suctioned to the tissue receiving opening, the target is bombarded with laser pulses from the laser fiber, wherein the laser pulses have sufficient energy to generate an optical breakdown in the target material and thereby generate a shockwave, which, at the tissue receiving opening, impinges on the tissue situated there and rips said tissue into small pieces which are then suctioned away through the suction channel. Furthermore, a longitudinally extending rinsing channel for guiding rinsing fluid through a laterally arranged emergence opening can additionally be provided in the needle.
U.S. Pat. No. 5,906,611 discloses a development of the instrument known from U.S. Pat. No. 5,324,282, in which the target has a step-shaped design and in which the steps are embodied with two step surfaces, of which one is aligned perpendicular to the needle axis and the other is aligned parallel to the needle axis, and the sequence of steps increases from an external side on the external wall of the needle toward the tissue receiving opening. As a result, when the target material is vaporized in each step zone of the target, the shockwave generated thereby is not blocked in the direction toward the tissue receiving opening by another part of the target. A neodymium-YAG laser can generate pulses with pulse repetition rates between 2 and 50 pulses per second and pulse energies between 2 and 15 mJ. The pulse duration can be set between 8 and 12 ns. The pulse repetition rate is preferably set between 2 and 6 pulses per second and the pulse energy is preferably set between 6 and 10 mJ. Between 200 and 800 pulses are used for a cataract operation.
A problem that occurs during surgical explantation or phacolysis of the natural eye lens and the subsequent implantation of an artificial intraocular lens is the subsequent growth and proliferation of the epithelial cells on the inner side of the lens capsular bag (PCO for posterior capsular bag opacification or secondary cataract or after cataract).
WO 2005/107665 A1 discloses a device for removing epithelial cells from the inner side of a lens capsular bag of a human or animal eye with means for generating pressure pulses in a liquid medium within the lens capsular bag, wherein the liquid medium adjoins or covers the epithelial cells to be removed, wherein the pressure pulses are selected or made in such a way that the epithelial cells are detached from the wall of the lens capsular bag by the impinging pressure pulses and, at the same time, no opening or other type of damage, in particular as a result of the pressure pulses, is created in the wall of the lens capsular bag when removing the epithelial cells. Use is preferably made of a laser handpiece in accordance with U.S. Pat. No. 5,324,282 or 5,906,611, but no negative pressure is created in the hollow needle in WO 2005/107665 A1 and no tissue is suctioned through the opening. Rather, the opening in the hollow needle in WO 2005/107665 A1 only serves for the emergence of the optically generated pressure pulses in the medium.